Longitudinal cutting devices are employed, for example, downstream of a rotary printing press in order to cut a web of material, and in particular a paper web which had been imprinted by the printing press. The web is cut longitudinally into a plurality of partial webs.
Particles, in the form of fine slivers, or dust, are released in the course of cutting the material web. A portion of these particles are removed from the longitudinal cutting device along with the web of material. However, another portion of these particles could adhere to the roller, where they can interfere with the further cutting process.
WO 96/07490 describes a process for the dust removal from a web of material with the aid of a high speed gas flow. It is assumed in this prior art document that efficient dust removal is only possible if a gas pressure of such a size is generated on the area from which dust is to be removed that the critical tension which is reversely proportional to the gas pressure is less than the electrostatic tension between the web of material and the particles stuck to it. This means that by generating a high pressure, the discharge of the particles, and therefore the cancellation of the electrostatic attraction, are promoted.
Although it is possible to clean a web of material prior to or after longitudinal cutting by the use of such a device, the device is not suitable for use in removing particles adhering to the roller of the cutting device itself. These particles then again pass through the contact zone with the cutting blade, which cutting blade may be, for example a circular cutting blade, with each revolution of the roller. The continued passage of these particles through the cutting zone can interfere with the cutting process.
JP 10-156706 AA shows a cutting device with a blower nozzle and a suction nozzle.
DE 631 858 C depicts a cutting device with a suction box and a scoop.
CH 613 881 A5 discloses a mechanism for dust removal. A blower nozzle is arranged in an inlet nip between a web and a roller. A suction nozzle is arranged at the end of the area of the roller on which the web or loop is formed.
DE 21 64 554 A shows a device for accomplishing the dust-free longitudinal cutting of running webs. A suction roller is provided underneath circular blades. The underpressure area is substantially limited to the area of the loop.
EP 0 183 863 A1 discloses a longitudinal cutting device in FIG. 7 with a blower nozzle on one side of the web. A suction nozzle, on the other side of the web, is assigned to this blower nozzle.
EP 0 608 498 A1 describes a device for cleaning a roller. A blower nozzle and a suction nozzle are arranged opposite the roller in the loop area of the web.